Tomer’s Take: A strong area of low pressure develops in FL on 12/17 then races up the Eastern Seaboard with wind and rain. The rain changes to snow in NY/VT/NH/ME on 12/19.
What’s next for the West? Precipitation hits CA late 12/17 as mainly rain. Rain/snow line runs 9k-10k on 12/17 and 12/18 then gradually falls. It looks like the Southern Branch will dominate the pattern through Christmas. This means a warmer than normal Christmas for UT, CO, WY, ID, MT, CA. Light snow hits the Southern Tier after 12/20, but more significant snow might hold off until after Christmas in UT, WY, ID, MT, and parts of CO.
My forecast video:
Crystal clear in Colorado this morning. View from the Divide at Loveland Ski Area:
Current Setup
Water vapor satellite shows energy sliding towards Florida that will develop into a strong East Coast storm system.
Also notice the large trough approaching CA.
Forecast Jet Stream
Valid 12/17. Trough approaches CA with warm air and precip.
Valid 12/24. Southern jet is main player with cold air trapped in Canada. Best snow chances are Southern Tier states.
Forecast Radar & Satellite
East Coast Storm System
Valid 11pm 12/17. Powerful area of low pressure with jet support and warm air. This storm might resemble the Superstorm of 1993 but it lacks cold air.
Valid 6am 12/18. Mainly rain 12/17-12/18 changing to light snow into 12/19 NY/VT/NH/ME.
Forecast Totals
Precipitation that hits CA late 12/17-12/18 is mainly rain below 10K.
CO Snow: 12/21, 12/24.
NM Snow: 12/21, 12/24.
Precipitation is rain 12/17-12/18 changing to snow into 12/19.
